Battery electrode plate reinforcement mat having improved wettability characteristics and methods of use therefor

ABSTRACT

According to one embodiment, a nonwoven fiber mat for reinforcing a plate or electrode of a lead-acid battery includes a plurality of glass fibers and an acid resistant binder that couples the plurality of glass fibers together. The nonwoven fiber mat also includes a wetting component that is applied to the glass fibers and/or nonwoven fiber mat to increase the wettability of the nonwoven fiber mat such that the nonwoven fiber mat exhibits an average water wick height of at least 0.5 cm after exposure to water for 10 minutes conducted according to method ISO8787. The wetting component may be dissolvable in an acid solution of the lead-acid battery such that a significant portion of the nonwoven fiber mat is lost due to dissolving of the wetting component.

BACKGROUND OF THE INVENTION

Lead-acid batteries are characterized as being inexpensive and highlyreliable. Therefore, they are widely used as an electrical power sourcefor starting motor vehicles or golf carts and other electric vehicles.Paper is commonly used as a means to improve the manufacturing processfor applying lead oxide or lead paste to the grid of a lead-acid batteryplate. A conventional pasting paper is made of fibers that will bedisintegrated over time by the sulfuric acid. This may lead to theformation of a gap between the lead plates or the lead plate and theseparator that might cause erosion of the lead plate, in particular dueto friction, thereby gradually deteriorating the performance of thebattery. Improved methods of manufacturing lead-acid battery plates aredesired.

BRIEF SUMMARY OF THE INVENTION

The embodiments described herein provide battery plate or electrodereinforcement mats having increased wettability properties orcapabilities. Such mats may aid in drying of the plate/electrode afterthe plate/electrode is pasted with a lead paste slurry. In addition, theintegrity or strength of such mats is sufficient to support theplate/electrode after assembly of the plate/electrode with a battery andduring usage of the battery. As such, the mats described herein aid inboth manufacturing of the plate/electrode and in reinforcing theplate/electrode.

According to one embodiment, a nonwoven fiber mat for reinforcing aplate or electrode of a lead-acid battery is provided. The nonwovenfiber mat (also referred to herein as a reinforcement mat) includes aplurality of glass fibers that may be either coarse fibers (e.g., fibershaving a diameter between about 6-30 μm or 8-30 μm), microfibers (e.g.,fibers having a diameter between about 0.01-5 μm), or a combination ofcoarse and microfibers. The nonwoven fiber mat also includes an acidresistant binder that couples the plurality of glass fibers together toform the mat. The nonwoven fiber mat further includes a wettingcomponent that is applied to nonwoven fiber mat to increase thewettability/wickability of the nonwoven fiber mat. Thewettability/wickability of the nonwoven fiber mat may be increased suchthat the nonwoven fiber mat has or exhibits an average water wick heightand/or water/acid solution wick height of at least 0.5 cm after exposureto water and/or the water/acid solution for 10 minutes in accordancewith a test conducted according to method ISO8787. The wetting componentmay be dissolvable in an acid solution such that a significant portionof the nonwoven fiber mat is lost due to dissolving of the wettingcomponent.

According to another embodiment, a method of manufacturing a nonwovenfiber mat for reinforcing a plate or electrode of a lead-acid battery isprovided. According to the method, a plurality of glass fibers may beprovided. The glass fibers may be coarse fibers, microfibers, or acombination of coarse and microfibers. An acid resistant binder may beapplied to the plurality of glass fibers to couple the plurality ofglass fibers together to form the nonwoven fiber mat. A wettingcomponent may be added to the glass fibers and/or nonwoven fiber mat toincrease the wettability/wickability of the nonwoven fiber mat. Thewettability/wickability of the nonwoven fiber mat may be increased suchthat the nonwoven fiber mat has or exhibits an average water wick heightand/or average water/acid solution wick height of at least 0.5 cm afterexposure to the respective solution for 10 minutes in accordance withthe test conducted according to method ISO8787.

According to another embodiment, an Absorptive Glass Mat (AGM) lead-acidbattery is provided. The AGM battery includes a positive plate orelectrode, a negative plate or electrode, a glass fiber mat separatorthat is disposed between the positive plate and the negative plate toelectrically insulate the positive and negative plates, and anelectrolyte that is absorbed within the glass fiber mat separator. Anonwoven fiber mat is positioned adjacent either or both the positiveplate or the negative plate so as to reinforce the positive plate or thenegative plate. The nonwoven fiber mat includes a plurality of glassfibers and an acid resistant binder that couples the plurality of glassfibers together to form the nonwoven fiber mat. The nonwoven fiber matalso includes a wetting component that is applied to the nonwoven fibermat to increase the wettability of the nonwoven fiber mat. Thewettability/wickability of the nonwoven fiber mat may be increased suchthat the nonwoven fiber mat has or exhibits an average water wick heightand/or average water/acid solution wick height of at least 0.5 cm afterexposure to the respective solution for 10 minutes in accordance withthe test conducted according to method ISO8787.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in conjunction with the appendedfigures:

FIG. 1 illustrates a nonwoven fiber mat for reinforcing a plate orelectrode of a lead-acid battery, according to an embodiment.

FIG. 2 illustrates a front exploded view of a lead-acid battery cell,according to an embodiment.

FIG. 3 is a method of manufacturing a nonwoven fiber mat for reinforcinga plate or electrode of a lead-acid battery, according to an embodiment.

FIG. 4 illustrates a process for manufacturing an electrode for alead-acid battery, according to an embodiment.

In the appended figures, similar components and/or features may have thesame numerical reference label. Further, various components of the sametype may be distinguished by following the reference label by a letterthat distinguishes among the similar components and/or features. If onlythe first numerical reference label is used in the specification, thedescription is applicable to any one of the similar components and/orfeatures having the same first numerical reference label irrespective ofthe letter suffix.

DETAILED DESCRIPTION OF THE INVENTION

The ensuing description provides exemplary embodiments only, and is notintended to limit the scope, applicability or configuration of thedisclosure. Rather, the ensuing description of the exemplary embodimentswill provide those skilled in the art with an enabling description forimplementing one or more exemplary embodiments. It being understood thatvarious changes may be made in the function and arrangement of elementswithout departing from the spirit and scope of the invention as setforth in the appended claims.

The embodiments described herein provide battery plate or electrodereinforcement mats having increased wettability properties orcapabilities. The term “wettability” as used herein refers to the matsability to wick or otherwise transport water and/or other solutions,such as a water and acid solution, from a location. For example, intesting the wettability or wickability of glass fiber mats, a strip ofthe mat, which is often about 1 inch in width, 6 inches long, andtypically 0.1-3 mm thick, may be dipped vertically in water or anothersolution for a given amount of time, such as 10 minutes. The distance orheight the water absorbs within the glass fiber mat from a surface ofthe water or other solution indicates the mat's ability to wick orotherwise transport the water or solution.

Conventional glass mats that are used to reinforce electrodes of aflooded lead-acid battery are often made of relatively coarse fibershaving fiber diameters that range between about 5 and 30 μm. Thesecoarse glass fiber mats often are not very wettable, such that whensubjected to the test above, the coarse glass fiber mats exhibit waterabsorption to a distance or height of close to zero. The reinforcementmats described herein (hereinafter reinforcement mats or nonwoven fibermats) are significantly more wettable than convention glass fiberreinforcement mats.

The reinforcement mats may be used for virtually any type of lead-acidbattery including flooded lead-acid batteries and Absorptive Glass Mat(AGM) lead-acid batteries. The mats may find a particular usefulness inAGM batteries due to the method in which the AGM electrodes or platesare manufactured. In manufacturing AGM electrodes a lead paste slurry isapplied to a lead grid. The lead paste slurry contains water and/or awater/acid solution (e.g., between about 15-65% by weight sulfuricacid). A glass fiber mat may then be applied over the lead paste slurryand lead grid to reinforce the electrode. After the application of thelead paste slurry and glass fiber mat, the electrode is typically driedto remove most of the water and/or water/acid solution. If aninsufficient amount of water and/or water/acid solution is removed fromthe electrode (i.e., the electrode contains too much water and/orwater/acid solution) the electrode may not function to its full capacityin the AGM battery and/or increase the internal resistance of thebattery.

Because conventional coarse glass fiber mats that are used forreinforcing electrodes are essentially non-wettable, or have negligiblewettability, these mats do not aid in the process or drying theelectrode to remove the water and/or water/acid solution. One problemwith such mats is that they are not very porous, which restricts thewater and/or water/acid solution of the lead paste slurry from coming tothe mat's surface where it can evaporate. As such, these conventionalglass fiber mats in essence trap the water and/or water/acid solutionwithin the electrode, which may result in an insufficient amount ofwater and/or water/acid solution being removed from the electrode. InAGM battery applications, these non-wettable glass mats may alsoseparate the electrode from the electrolyte that is absorbed within thebattery separator.

The reinforcement mats described herein increase the wettability ofglass fiber mats by adding a wetting component to the glass fiber mats.The added wetting component provides an avenue for the water and/orwater/acid solution to evaporate. In one embodiment, the added wettingcomponent aids in the transport of water and/or water/acid solution to asurface of the mat where the water and/or water/acid solution mayevaporate. In some embodiments, the added wetting component may bedissolvable by the acid in the solution such that a significant amountof the mat's mass is lost after the added wetting component dissolves.For example, in some embodiments the mat may lose between about 15 and85% of the mat's mass after the added wetting component dissolves. Themat may be configured to reinforce the electrode even after the addedwetting component is dissolved and the mat's mass is decreased.

In one embodiment, the added wetting component may be a wettablecomponent of an acid resistant binder that is used to bond the glassfibers of the reinforcement mat together. The wettable component may bea hydrophilic functional group that increases the ability of the waterand/or water/acid solution to absorb within the glass reinforcement mator flow along a surface of the glass reinforcement mat. In otherembodiments, wettable component may be a hydrophilic binder that isblended or combined with the acid resistant binder to form a bindermixture. The hydrophilic binder may be dissolvable in an acid solution.In some embodiments, the wettable component may include starch,cellulose, a hydrophilic binder (e.g., a poly acrylic acid based binder)and the like. The wettable component may dissolve in the acid solutionof a battery electrode, which results in a glass mat and acid resistantbinder upon dissolving of the wettable component. In some embodiments,the glass reinforcement mat may include only coarse glass fibers, orfibers having a fiber diameter of between about 8 and 30 μm. Thewettable component may increase such mat's ability to absorb the waterand/or water/acid solution and/or allow the water and/or water/acidsolution to flow essentially along a surface of the reinforcement mat.

As used herein, the term hydrophilic (or acidophilic) binder refers to abinder having a contact angle with water (or a 33 wt. % sulfuric acidmedium for acidophilic) of less than about 90°, preferably less than70°, and most preferably less than 50°. In testing the contact angle ofthe binder, the binder may be spin-coated on a glass slide and thencured before being exposed to the above solution to measure the contactangle.

In other embodiments, the glass reinforcement mat may include acombination of coarse glass fibers (i.e., glass fibers having diametersbetween about 8 and 30 μm) and microfibers, or fibers having a fiberdiameter of between about 0.01 and 5 μm. These glass mats may includebetween 40-80% coarse glass fibers and 20-60% glass microfibers. Thecoarse fibers and/or binder may limit or restrict the exposure of thewater and/or water/acid solution to the glass microfibers, which aretypically more wettable or wickable than the coarse fibers. The coarsefibers and/or binder may conceal or cover the microfibers, which limitsor restricts exposure of the water and/or water/acid solution to themicrofibers. The wettable component may increase the exposure of thewater and/or water/acid solution to the glass microfibers, such as byproviding an avenue to the microfibers, which may aid in the transportof the water and/or water/acid solution to the surface of thereinforcement mat and in evaporation of the water and/or water/acidsolution.

In some embodiments, the binder and wettable component may be added tothe reinforcement mat up to about 20% LOI (Loss on Ignition). In otherembodiments, a first binder that does not include a wettable componentmay be used to bond the coarse glass fibers and/or glass microfibers,and a second binder having the wettable component (e.g., a hydrophilicfunctional group) may be applied to the reinforcement mat to increasethe wettablity of the mat. The first and second binders may be mixed orcombined together to form a single binder mixture that is applied to thecoarse glass fibers and/or glass microfibers.

In another embodiment, the added wetting component may be a fiber thatreacts with the acid solution (e.g., sulfuric acid) of the battery sothat the fiber dissolves upon exposure to the acid solution. The fibermay be a natural fiber, such as cellulose (hereinafter componentfibers). The component fibers may have a microfiber structure, or inother words may have fiber diameters between about 0.01 and 5 μm. Thewickability/wettability of the component fibers may be better than theglass fibers (e.g., coarse fibers in the range of 8-30 μm) due to thestructure of the fibers (e.g., microfibers) and/or because the componentfibers typically include hydrophilic functional groups, such as OHgroups, COOH groups, and the like.

In some embodiments, the component fibers may be formed into a mat thatis separate from the mat of glass fibers, such as by applying thecomponent fibers atop a glass fiber mat. The component fiber mat may bebonded with the glass fiber mat so that the resulting combined mat hasessentially two layers—a layer of glass fibers and a layer of componentfibers. In some embodiments, a second component fiber mat may be bondedto an opposite side of the glass fiber mat so that the resultingcombined mat has essentially three layers—a glass mat sandwiched betweentwo component fiber mats. In another embodiment, the component fibersmay be mixed with the glass fibers so that the resulting mat includes acombination of entangled glass fibers and component fibers. An acidresistant binder may be used to bond the component fiber mat with theglass fiber mat, or may be used to bond the entangled glass fibers andcomponent fibers to form the reinforcement mat.

In one embodiment, the glass fiber mat may include mainly coarse fibers,or fibers having a fiber diameter of between about 5 and 30 μm. In someembodiments, other acid resistant fibers may be used instead of glassincluding polyethylene fibers, polypropylene fibers, polyester fibers,and the like. The component fibers (e.g. cellulose fibers) provide thereinforcement mat with good wetting properties by aiding in thetransport of water and or a water/acid solution to the surface of thereinforcement mat where the water and/or water/acid solution mayevaporate. As described above, the component fibers may be dissolvableby the acid in the solution (e.g. sulfuric acid) such that a significantamount of the mat's mass is lost after the component fibers dissolve. Insome embodiments, the reinforcement mat may include between about 15-85%of the coarse fibers and between about 15-85% of the component fibers.The component fibers may be exposed to a solution containing betweenabout 15-65% by weight of sulfuric acid, which may cause the componentfibers to dissolve. In such embodiments, the mat may lose up to 5-85% ofits mass upon dissolving of the component fibers, and more commonly losebetween 15-50% of its mass. The coarse fibers used to make the mat aresufficiently strong so as to reinforce the electrode after the componentfibers are dissolved.

In another embodiment, the glass fiber mat may include mainly glassmicrofibers, or fibers having a fiber diameter of between about 0.01 and5 μm. The resulting reinforcement mat may include mainly or only glassmicrofibers that are entangled with the components fibers, or that arebonded with a component fiber mat(s). Such a reinforcement mat may haveexceptional wetting and wicking capabilities. The component fibers maydissolve when exposed to the acid solution such that the glassmicrofibers remain adjacent the electrode subsequent to dissolving ofthe component fibers.

In some embodiments, the reinforcement mat may include a combination ofcoarse acid resistant fibers (e.g., fibers having a fiber diameter ofbetween 5 and 30 μm), acid resistant microfibers (e.g., fibers having afiber diameter of between 0.01 and 5 μm), and the component fibers. Theacid resistant coarse fibers and microfibers are commonly glass fibers,although other acid resistant fibers may be used. In some embodiments,the reinforcement mat may include between about 15-85% of thecombination of glass coarse and microfibers, and between about 15-85% ofthe component fibers. In another embodiment, the reinforcement mat mayinclude between about 40-60% of the coarse glass fibers, 20-30% of theglass microfibers, and 20-30% of the component fibers. The componentfibers and microfibers may function synergistically to wick water and/orthe water/acid solution, and thus, may greatly improve thewettability/wickability of the reinforcement mat. For example, glassmicrofibers are typically more wettable than coarse glass fibers. Themicrofibers, however, may be covered or concealed by the coarse glassfibers and/or binder and, thus, not exposed to the water and/orwater/acid solution.

The addition of the component fibers within, or adjacent a surface of,the reinforcement mat may greatly improve the exposure of the waterand/or water/acid solution to the glass microfibers, thereby enablingthe water and/or water/acid solution to access the glass microfibers andbe wicked or transported to a surface of the mat for evaporation. Inthis manner, the microfibers and component fibers functionsynergistically to wick or transport the water and/or water/acidsolution for eventual evaporation. The addition of the glass microfibersto a reinforcement mat that includes the coarse and component fibers maygreatly increase the wettability/wickability of the reinforcement mat.

In some embodiments, the binder having the wettable component (e.g., ahydrophilic functional group) may be used to bond a reinforcement matthat includes the coarse glass and component fibers, or that includesthe coarse glass fibers, glass microfibers, and component fibers. Thewettable component may further increase the wettability of thereinforcement mats, such as by providing another avenue for transport ofthe water and/or water/acid solution and/or by increasing the exposureof the water and/or water/acid solution to the glass microfibers.

In another embodiment, the added wetting component may be a wettablesolution that is added to the reinforcement mat. The wettable solutionmay be added to the reinforcement mat so as to saturate thereinforcement mat, or so as to be disposed on at least one surface ofthe reinforcement mat after drying of the wettable solution. Thewettable solution may include a starch solution, cellulose solution,polyvinyl alcohol solution, polyacrylic acid solution, and the like. Thewettable solution may be added to the mat after the mat is formed, suchas by dip-coating the reinforcement mat in the wettable solution, or byapplying the wettable solution via spray coating, curtain coating, andthe like. After application of the wettable solution, the wettablesolution may be dried to provide an avenue for the water and/orwater/acid solution to evaporate. The wettable solution may subsequentlydissolve when exposed to an acid environment, such as the environment ofthe battery's electrode, so that the reinforcement mat remains adjacentthe electrode after dissolving of the wettable solution.

According to any of the embodiments described herein, the addition ofthe wetting component to the reinforcement mat may increase thewettability of the reinforcement mat such that the reinforcement matexhibits an average water wick height of at least 0.5 cm after exposureto water for 10 minutes. The test to determine the average water wickheight of the reinforcement mat may be conducted according to methodISO8787. Similarly, the addition of the wetting component to thereinforcement mat may enable the reinforcement mat to exhibit an averagewater/acid solution wick height of at least 0.5 cm after exposure to thewater/acid solution for 10 minutes. This test is similarly conductedaccording to method ISO8787. In other embodiments, the average waterwick height and/or water/acid solution wick height may be at least 0.8cm after exposure to the respective solution for 10 minutes. In yetother embodiments, the average water wick height and or water/acidsolution wick height may be greater than 1 cm after exposure to therespective solution for 10 min. As briefly described above, the additionof glass microfibers to the reinforcement mat may significantly increasethe wettability/wickability of the reinforcement mat such that theaverage water wick height and/or water/acid solution wick heightincreases.

Embodiments

Referring now to FIG. 1, illustrated is an embodiment of a nonwovenfiber mat 100 for reinforcing a plate or electrode of a lead-acidbattery (hereinafter reinforcement mat 100). The reinforcement mat 100includes a plurality of glass fibers that may be either coarse fibers(e.g., fibers having a diameter between about 5-30 μm), microfibers(e.g., fibers having a diameter between about 0.01-5 μm), or acombination of coarse and microfibers as described herein. Reinforcementmat 100 also includes an acid resistant binder that couples theplurality of glass fibers together to form the mat. The reinforcementmat 100 further includes a wetting component that is applied toreinforcement mat 100 to increase the wettability/wickability of thereinforcement mat. The wettability/wickability of the reinforcement mat100 may be increased such that the reinforcement mat has or exhibits anaverage water wick height and/or water/acid solution wick height of atleast 0.5 cm after exposure to the respective solution for 10 minutes inaccordance with a test conducted according to method ISO8787. Asdescribed previously, the wetting component is dissolvable in an acidsolution of the lead-acid battery such that a significant portion of thereinforcement mat 100 is lost due to this dissolving of the wettingcomponent. In one embodiment, the reinforcement mat 100 may lose betweenabout 5-85% of its mass due to dissolving of the wetting component, andmore commonly lose between 15-50% of its mass.

As described herein, in some embodiments the wetting component may bewettable component of the acid resistant binder (e.g., a hydrophilicfunctional group) or a hydrophilic binder that is mixed/combined withthe acid resistant binder. In other embodiments, the wetting componentmay be a wettable solution (e.g. starch or cellulose solution) that isapplied to the reinforcement mat 100 so that the wettable solutionsaturates the reinforcement mat 100 or is disposed on at least onesurface of the reinforcement mat 100 after the wettable solution isdried. In still another embodiment, the wetting component may be aplurality of component fibers (e.g., cellulose or other natural fibers)that are bonded with the reinforcement mat 100. According to oneembodiment, the component fibers may form a component fiber mat that isbonded to at least one side of the reinforcement mat 100 such that thereinforcement mat 100 comprises a two layer mat configuration. Inanother embodiment, the component fibers may be mixed with the glassfibers such that upon forming the reinforcement mat 100 and componentfibers are entangled with and bonded to the glass fibers. In yet otherembodiments, the wetting component may be a combination of the abovedescribed wetting components (i.e., a binder having a wettablecomponent, a wettable solution, and/or a component fiber).

In a specific embodiment, reinforcement mat 100 includes a plurality offirst glass fibers having fiber diameters between about 5-30 μm and aplurality of second glass fibers having fiber diameters between about0.01-5 μm. The addition of the second glass fibers may significantlyincrease the wettability/wickability of the reinforcement mat 100 suchthat the reinforcement mat 100 has or exhibits an average water wickheight and/or average water/acid solution wick height of at least 1.0 cmafter exposure to the respective solution for 10 minutes in accordancewith a test conducted according to method ISO8787. In some embodiments,reinforcement mat 100 has a thickness of between 0.1 and 1 mm under 10KPa pressure.

Referring now to FIG. 2, illustrated is front exploded view of alead-acid battery cell 200. The lead-acid batter cell 200 may representa cell used in either flooded lead-acid batteries or Absorptive GlassMat (AGM) batteries. Each cell 200 may provide an electromotive force(emf) of about 2.1 volts and a lead-acid battery may include 3 suchcells 200 connected in series to provide an emf of about 6.3 volts ormay include 6 such cells 200 connected in series to provide an emf ofabout 12.6 volts, and the like. Cell 200 includes a positive plate orelectrode 202 and a negative plate or electrode 212 separated by batteryseparator 220. Positive electrode 202 includes a grid or conductor 206of lead alloy material. A positive active material (not shown), such aslead dioxide, is typically coated or pasted on grid 206. Grid 206 isalso electrically coupled with a positive terminal 208. A reinforcementmat 204, such as those described herein, is coupled with grid 206 andthe positive active material. Reinforcement mat 204 provides structuralsupport for the grid 206 and positive active material.

Similarly, negative electrode 212 includes a grid or conductor 216 oflead alloy material that is coated or pasted with a negative activematerial (not shown), such as lead. Grid 216 is electrically coupledwith a negative terminal 218. A reinforcement mat 214, such as thosedescribed herein, is also coupled with grid 216 and the negative activematerial. Reinforcement mat 214 provides structural support for the grid216 and negative active material. In flooded type lead-acid batteries,positive electrode 202 and negative electrode 212 are immersed in anelectrolyte (not shown) that may include a sulfuric acid and watersolution. In AGM type lead-acid batteries, the electrolyte is absorbedand maintained within battery separator 220. Battery separator 220 ispositioned between positive electrode 202 and negative electrode 212 tophysically separate the two electrodes while enabling ionic transport,thus completing a circuit and allowing an electronic current to flowbetween positive terminal 208 and negative terminal 218. Separator 220typically also includes a microporous membrane, which is often apolymeric film having negligible conductance. The polymeric film mayinclude micro-sized voids that allow ionic transport (i.e., transport ofionic charge carriers) across separator 220.

As described herein, reinforcement mat 204 and/or 214 includes aplurality of glass fibers, an acid resistant binder that couples theplurality of glass fibers together to form the reinforcement mat. Thereinforcement mat 204 and/or 214 also includes a wetting component thatis applied to the reinforcement mat to increase thewettability/wickability of the reinforcement mat. Thewettability/wickability of the reinforcement mat 204 and/or 214 isincreased so that the reinforcement mat has or exhibits an average waterwick height and/or average water/solution wick height of at least 0.5 cmafter exposure to the respective solution for 10 minutes in accordancewith a test conducted according to method ISO8787. The wetting componentis dissolvable in an acid solution of cell 200 such that a significantportion of the reinforcement mat 204 and/or 214 is lost due todissolving of the wetting component as described herein.

As described herein, the wetting component may be a wettable componentof the acid resistant binder (e.g., a hydrophilic functional group), ahydrophilic binder that is mixed with the acid resistant binder, thewetting component may be component fibers (e.g., cellulose or naturalfibers) that are bonded with the glass fibers of the reinforcement mat204 and/or 214, or the wetting component may be a wettable solution(e.g., starch or cellulose solution) that is applied to thereinforcement mat 204 and/or 214 such that the wettable solutionsaturates the reinforcement mat 204 and/or 214 or is disposed on atleast one surface of the reinforcement mat 204 and/or 214 upon drying ofthe wettable solution. In some embodiments, the wetting component mayinclude a combination of any of the aforementioned components, such as acombination of cellulose fibers and an acid resistant binder having awettable component. In a specific embodiment, the glass fibers ofreinforcement mat 204 and/or 214 include first fibers having fiberdiameters between about 6 μm and about 30 μm, or 8 μm and about 30, μmand second fibers having fiber diameters between 0.01 μm and 5 μm.

Referring now to FIG. 4, illustrated is a process 400 for manufacturingan electrode for a lead-acid battery, such as a flooded type lead-acidbattery and/or AGM battery. The process may involve transporting a leadalloy grid 410 on a conveyor toward an active material 430 applicator(e.g., lead or lead oxide paste applicator), which applies or pastes aslurry of the active material 430 to the grid 410. The slurry of theactive material may have a relatively high water and/or water/acidsolution content that needs to be dried or removed at some point duringthe manufacture of the electrode. A reinforcement mat roll 420 may bepositioned below grid 410 so that a reinforcement mat is applied to abottom surface of the grid 410. The reinforcement mat may include theglass fibers and wetting component as described herein. In someembodiments, the reinforcement mat may also include a blend of coarseand micro glass fibers in addition to the wetting component as describedherein. In some embodiments, a second reinforcement mat roll 440 may bepositioned above grid 410 so that a second reinforcement mat is appliedto a top surface of the grid 410. The second reinforcement mat may alsoinclude the glass fibers and wetting component and/or a blend of coarseand micro glass fibers in addition to the wetting component as describedherein. The second reinforcement mat may be similar to or different fromthe first reinforcement mat.

The resulting electrode or plate 450 may subsequently be cut to lengthvia a plate cutter (not shown). The active material 430 may be appliedto the grid 410 and/or top and bottom of reinforcement mats, 440 and420, so that the active material impregnates or saturates thereinforcement mats to some degree. The electrode or plate 450 may thenbe dried via a dryer 460 or other component of process 400. As describedherein, the reinforcement mats, 440 and 420, may aid in the drying ofthe electrode or plate 450 by wicking the water and/or water/acidsolution from the electrode or plate 450 so as to allow the water and/orwater/acid solution to evaporate.

Referring now to FIG. 3, illustrated is an embodiment of a method 300 ofmanufacturing a nonwoven fiber mat for reinforcing a plate or electrodeof a lead-acid battery (hereinafter reinforcement mat). At block 310, aplurality of glass fibers are provided. The glass fibers may be coarsefibers, microfibers, or a combination of coarse and microfibers. Atblock 320, an acid resistant binder is applied to the plurality of glassfibers to couple the plurality of glass fibers together to form thereinforcement mat. At block 330, a wetting component is added to theglass fibers and/or reinforcement mat to increase thewettability/wickability of the reinforcement mat. As described herein,the wettability/wickability of the reinforcement mat may be increasedsuch that the reinforcement mat has or exhibits an average water wickheight and/or average water/acid solution wick height of at least 0.5 cmafter exposure to the respective solution for 10 minutes in accordancewith the test conducted according to method ISO8787.

In some embodiments, method 300 may further include exposing thereinforcement mat to an acid solution to dissolve the wetting component.For example, after the components of the battery are assembled (e.g.,the separator, electrodes/plates, battery case, and the like), an acidelectrolyte solution is introduced into the battery's interior and thebattery is closed and/or sealed. Exposure of the reinforcement mat tothe acidic electrolyte solution may dissolves the wetting component.Dissolving of the wetting component may result in a significant portionof the reinforcement mat being lost or eliminated as described herein.For example, in some embodiments between about 15-85% of the mass of thereinforcement mat may be lost due to dissolving of the wetting componentin the acid solution. In some embodiments, the reinforcement mat may beexposed to between 15-65% by weight of the acid solution.

In some embodiments, applying the wetting component includes applyingthe acid resistant binder, where the acid resistant binder includes awettable component (e.g., a hydrophilic functional group, a hydrophilicand acid resistant binder mixture, and the like) that functions toincrease the wettability/wickability of the nonwoven fiber mat. Inanother embodiment, applying the wetting component includes applying awettable solution (e.g., starch or cellulose solution and the like) tothe reinforcement mat such that the wettable solution saturates thereinforcement mat or is disposed on at least one surface of thereinforcement mat upon drying of the wettable solution.

In yet another embodiment, applying the wetting component includesbonding a plurality of component fibers (e.g., cellulose fibers and thelike) with the plurality of glass fibers of the reinforcement mat. Insuch embodiments, the reinforcement mat may include between about 40-95%of the glass fibers and 5-50% of the cellulose fibers, and more commonlybetween about 10-30% of the cellulose fibers. In a specific embodiment,the reinforcement mat may include between about 40-60% of the glassfibers and 40-60% of the cellulose fibers. In still further embodiments,applying the wetting component may include applying any combination ofthe wetting components described herein, such as the component fibers,wettable solution, and/or acid resistant binder having a wettablecomponent.

In some embodiments, the plurality of glass fibers may include firstglass fibers having fiber diameters between about 8 μm and about 30 μm.In such embodiments, the method 300 may further include providing aplurality of second glass fibers having fiber diameters between about0.01 μm and about 5 μm and bonding the plurality of second glass fiberswith the first glass fibers via the acid resistant binder. The additionof the second glass fibers may increase the wettability/wickability ofthe reinforcement mat such that the reinforcement mat has or exhibits anaverage water wick height and/or an average water/acid solution wickheight of at least 1.0 cm after exposure to the respective solution for10 minutes in accordance with the test conducted according to methodISO8787. In some embodiments, component fibers (e.g., cellulose fibersand the like) may be bonded with the plurality of first glass fibers andthe plurality of second glass fibers. In such embodiments, thereinforcement mat may include between about 40-80% of the first glassfibers, 10-50% of the second glass fibers, and 5-40% of the cellulosefibers. In another embodiment, the reinforcement mat may include betweenabout 40-50% of the first glass fibers, 20-30% of the second glassfibers, and 20-30% of the cellulose fibers.

EXAMPLES

Several reinforcement mats were manufactured in accordance with theembodiments described herein and tested to determine thewettability/wickability of the mats. The wettability/wickability testswere conducted according to method ISO8787. The mats were exposed toboth a water solution and a water/acid solution where the concentrationof sulfuric acid was approximately 40%. The results of the tests areshown in Table 1 below.

TABLE 1 Sample Reinforcement Mat Average Average acid water wickingwicking (40%) height height after after Sample Sample 10 mins Std 10mins Std ID description Binder (cm) Dev (cm) Dev Control 100% RHOPLEX ™0.0 0 0.0 0.0 coarse HA-16 glass fibers 1 50% 3/4″ RHOPLEX ™ 0.8 0.151.2 0.12 K249 T, HA-16 50% cellulose 2 50% 3/4″ Hycar ® FF 0.9 0.15 0.90.15 K249 T, 26903 50% cellulose 3 50% 3/4″ Hycar ® FF 2.7 0.05 1.9 0.25K249 T, 26903 25% cellulose, 25% 206- 253

A control mat was also manufactured and tested to provide a comparisonor reference point for the other tested mats. The control mat includes100% coarse glass fibers (T glass fibers) having an average fiber lengthof approximately ¾″ and an average fiber diameter of approximately 13μm. The glass fibers were bond together with an acid resistant bindersold by Dow Chemical under the trade name RHOPLEX™ HA-16. The acidresistant binder was applied so as to have a Loss on Ignition (LOI) ofapproximately 20%. The control mat exhibited an average water wickingheight and an average acid wicking height of approximately 0.0 cm afterexposure to the respective solutions for 10 minutes. Stated differently,the control mat exhibited essentially no wettability/wickability.

A first mat (i.e. Sample ID 1) was manufactured to include approximately50% coarse glass fibers having an average fiber length of approximately¾″ and an average fiber diameter of approximately 13 μm and to include50% cellulose fibers having an average fiber length of approximately2.40 mm. The cellulose fibers were made from a pulp slurry bypre-soaking a Kraft board in water (e.g., Kamloops Chinook Kraft boardmanufacture by Domtar) and stirring the soaked Kraft board in water forat least 10 minutes. The cellulose fiber pulp slurry was then combinedwith the glass fibers. The coarse glass fibers and cellulose fibers werebond together with the RHOPLEX™ binder so as to have an LOI ofapproximately 20%. The first mat exhibited an average water wickingheight of approximately 0.8 cm with a standard deviation of 0.15 afterexposure to the water solution for 10 minutes. The first mat alsoexhibited an average water/acid solution wicking height of approximately1.2 cm with a standard deviation of 0.12 after exposure to thewater/acid solution for 10 min.

A second mat (i.e. Sample ID 2) was manufactured to includeapproximately 50% coarse glass fibers and 50% cellulose fibers havingfiber properties similar to the first mat. The coarse glass fibers andcellulose fibers were bond together with an acid resistant binder soldby Lubrizol under the trade name Hycar® FF 26903. The binder was appliedso as to have an LOI of approximately 20%. The second mat exhibited anaverage water wicking height of approximately 0.9 cm with a standarddeviation of 0.15 after exposure to the water solution for 10 minutes.The second mat also exhibited an average water/acid solution wickingheight of approximately 0.9 cm with a standard deviation of 0.15 afterexposure to the water/acid solution for 10 min.

A third mat (i.e. Sample ID 3) was manufactured to include approximately50% coarse glass fibers and 25% cellulose fibers having fiber propertiessimilar to the first and second mats. The third mat also includedapproximately 25% glass microfibers having an average fiber diameter ofapproximately 0.76 μm (i.e., Johns Manville 206-253 fibers). The coarseglass fibers, glass microfibers, and cellulose fibers were bond togetherwith the Hycar® binder so as to have an LOI of approximately 20%. Thethird mat exhibited an average water wicking height of approximately 2.7cm with a standard deviation of 0.05 after exposure to the watersolution for 10 minutes. The third mat also exhibited an averagewater/acid solution wicking height of approximately 1.9 cm with astandard deviation of 0.25 after exposure to the water/acid solution for10 min.

As shown in the test results above, the addition of the wettingcomponent to the reinforcement mat, which in this case includedcellulose fibers, significantly increased the wettability/wickability ofthe reinforcement mat. Further, the inclusion of glass microfibers inthe reinforcement mat in addition to the wetting component significantlyincreased the wettability/wickability of the reinforcement mat beyondthat exhibited by adding the wetting component alone.

Having described several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theinvention. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent invention. Accordingly, the above description should not betaken as limiting the scope of the invention.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimits of that range is also specifically disclosed. Each smaller rangebetween any stated value or intervening value in a stated range and anyother stated or intervening value in that stated range is encompassed.The upper and lower limits of these smaller ranges may independently beincluded or excluded in the range, and each range where either, neitheror both limits are included in the smaller ranges is also encompassedwithin the invention, subject to any specifically excluded limit in thestated range. Where the stated range includes one or both of the limits,ranges excluding either or both of those included limits are alsoincluded.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural referents unless the context clearly dictatesotherwise. Thus, for example, reference to “a process” includes aplurality of such processes and reference to “the device” includesreference to one or more devices and equivalents thereof known to thoseskilled in the art, and so forth.

Also, the words “comprise,” “comprising,” “include,” “including,” and“includes” when used in this specification and in the following claimsare intended to specify the presence of stated features, integers,components, or steps, but they do not preclude the presence or additionof one or more other features, integers, components, steps, acts, orgroups.

What is claimed is:
 1. A nonwoven fiber mat for reinforcing a plate or electrode of a lead-acid battery, the nonwoven fiber mat comprising: a plurality of glass fibers; an acid resistant binder that couples the plurality of glass fibers together to form the nonwoven fiber mat; and a wetting component applied to the nonwoven fiber mat to increase the wettability of the nonwoven fiber mat such that the nonwoven fiber mat has or exhibits an average water wick height of at least 0.5 cm after exposure to water for 10 minutes conducted according to method ISO8787, wherein the wetting component is dissolvable in an acid solution of the lead-acid battery such that a significant portion of the nonwoven fiber mat is lost due to dissolving of the wetting component.
 2. The nonwoven fiber mat of claim 1, wherein the wetting component comprises a hydrophilic functional group of the acid resistant binder.
 3. The nonwoven fiber mat of claim 1, wherein the wetting component comprises a hydrophilic binder that is blended or combined with the acid resistant binder, wherein the hydrophilic binder is dissolvable in acid.
 4. The nonwoven fiber mat of claim 1, wherein the wetting component comprises a plurality of cellulose fibers that are bonded with the nonwoven fiber mat.
 5. The nonwoven fiber mat of claim 4, wherein the cellulose fibers form a cellulose fiber mat that is bonded to at least one side of the nonwoven fiber mat.
 6. The nonwoven fiber mat of claim 4, wherein the cellulose fibers are entangled with the glass fibers to form the nonwoven fiber mat.
 7. The nonwoven fiber mat of claim 1, wherein the wetting component comprises a starch solution that is applied to the nonwoven fiber mat such that the starch solution saturates the nonwoven fiber mat or is disposed on at least one surface of the nonwoven fiber mat.
 8. The nonwoven fiber mat of claim 1, wherein the significant portion of the nonwoven fiber mat that is lost due to dissolving of the wetting component comprises between about 5-85% of the mass of the nonwoven fiber mat.
 9. The nonwoven fiber mat of claim 1, wherein the plurality of glass fibers comprise first glass fibers having fiber diameters between about 8 μm and about 30 μm, and wherein the nonwoven mat further comprises a plurality of second glass fibers that are entangled with the first glass fibers, wherein the second glass fibers have fiber diameters between about 0.01 μm and about 5 μm, and wherein the addition of the second glass fibers increases the wettability of the nonwoven fiber mat such that the nonwoven fiber mat has or exhibits an average water wick height of at least 1.0 cm after exposure to water for 10 minutes conducted according to method ISO8787.
 10. The nonwoven fiber mat of claim 1, wherein the nonwoven fiber mat has or exhibits an average acid solution wick height of at least 0.5 cm after exposure to the acid solution for 10 minutes conducted according to method ISO8787.
 11. The nonwoven fiber mat of claim 1, wherein the lead-acid battery comprises an Absorptive Glass Mat (AGM) battery or a flooded batter.
 12. A method of manufacturing a nonwoven fiber mat for reinforcing a plate or electrode of a lead-acid battery, the method comprising: providing a plurality of glass fibers; applying an acid resistant binder to the plurality of glass fibers to couple the plurality of glass fibers together to form the nonwoven fiber mat; and applying a wetting component to the nonwoven fiber mat to increase the wettability of the nonwoven fiber mat such that the nonwoven fiber mat has or exhibits an average water wick height of at least 0.5 cm after exposure to water for 10 minutes conducted according to method ISO8787.
 13. The method of claim 12, further comprising exposing the nonwoven fiber mat to an acid solution to dissolve the wetting component, wherein a significant portion of the nonwoven fiber mat is lost due to dissolving of the wetting component.
 14. The method of claim 13, wherein the significant portion of the nonwoven fiber mat that is lost due to dissolving of the wetting component comprises between about 5-85% of the mass of the nonwoven fiber mat.
 15. The method of claim 13, wherein the nonwoven fiber mat is exposed to between 15-65% by weight of the acid solution.
 16. The method of claim 12, wherein applying the wetting component comprises applying the acid resistant binder, the acid resistant binder including a hydrophilic functional group that functions as the wetting component to increase the wettability of the nonwoven fiber mat.
 17. The method of claim 12, wherein applying the wetting component comprises bonding a plurality of cellulose fibers with the plurality of glass fibers of the nonwoven fiber mat.
 18. The method of claim 17, wherein the nonwoven fiber mat comprises between about 40-60% of the glass fibers and 40-60% of the cellulose fibers.
 19. The method of claim 12, wherein applying the wetting component comprises applying a starch solution to the nonwoven fiber mat such that the starch solution saturates the nonwoven fiber mat or is disposed on at least one surface of the nonwoven fiber mat.
 20. The method of claim 12, wherein the plurality of glass fibers comprise first glass fibers having fiber diameters between about 8 μm and about 30 μm and wherein the method further comprises: providing a plurality of second glass fibers having fiber diameters between about 0.01 μm and about 5 μm; and bonding the plurality of second glass fibers with the first glass fibers via the acid resistant binder, wherein the addition of the second glass fibers increases the wettability of the nonwoven fiber mat such that the nonwoven fiber mat has or exhibits an average water wick height of at least 1.0 cm after exposure to water for 10 minutes conducted according to method ISO8787.
 21. The method of claim 20, wherein the wetting component comprises cellulose fibers that are bonded with the plurality of first glass fibers and the plurality of second glass fibers, and wherein the nonwoven fiber mat comprises between about 40-80% of the first glass fibers, 10-50% of the second glass fibers, and 5-40% of the cellulose fibers.
 22. An Absorptive Glass Mat (AGM) lead-acid battery comprising: a positive plate or electrode; a negative plate or electrode; a separator that is disposed between the positive plate and the negative plate to electrically insulate the positive and negative plates; an electrolyte that is absorbed within the separator; and a nonwoven fiber mat that is positioned adjacent either or both the positive plate or the negative plate so as to reinforce the positive plate or the negative plate, wherein the nonwoven fiber mat comprises: a plurality of glass fibers; an acid resistant binder that couples the plurality of glass fibers together to form the nonwoven fiber mat; and a wetting component applied to the nonwoven fiber mat to increase the wettability of the nonwoven fiber mat such that the nonwoven fiber mat comprises or exhibits an average water wick height of at least 0.5 cm after exposure to water for 10 minutes conducted according to method ISO8787, wherein the wetting component is dissolvable in an acid solution of the lead-acid battery such that a significant portion of the nonwoven fiber mat is lost due to dissolving of the wetting component.
 23. The AGM lead-acid battery of claim 22, wherein the wetting component comprises a hydrophilic functional group of the acid resistant binder.
 24. The AGM lead-acid battery of claim 22, wherein the wetting component comprises a plurality of cellulose fibers that are bonded with the nonwoven fiber mat.
 25. The AGM lead-acid battery of claim 22, wherein the wetting component comprises a starch solution that is applied to the nonwoven fiber mat such that the starch solution saturates the nonwoven fiber mat or is disposed on at least one surface of the nonwoven fiber mat.
 26. The AGM lead-acid battery of claim 22, wherein the glass fibers comprise first fibers having fiber diameters between about 8 μm and about 30 μm or second fibers having fiber diameters between 0.01 μm and 5 μm. 